bpo-34162: Add entry for idlelib/NEWS.txt already included for 3.6/3.7 (GH-9549)

diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt
index 6b08408..273f7c4 100644
--- a/Lib/idlelib/NEWS.txt
+++ b/Lib/idlelib/NEWS.txt
@@ -3,6 +3,11 @@
 ======================================
 
 
+bpo-33975: Avoid small type when running htests.
+Since part of the purpose of human-viewed tests is to determine that
+widgets look right, it is important that they look the same for testing
+as when running IDLE.
+
 bpo-33905: Add test for idlelib.stackview.StackBrowser.
 
 bpo-33924: Change mainmenu.menudefs key 'windows' to 'window'.